Hands on sessions

Elaboration on Hands on sessions

In-situ crystal orientation mapping in the SEM. In this workshop, you will get hands on experiences in performing Transmission Kikuchi Diffraction (TKD) in the SEM while annealing an electron transparent sample. You will be introduced to automated crystal orientation mapping in the SEM and to some of the parameters influencing the quality of the data. You will follow the microstructure evolution and extract quantitative data on grain growth, grain boundary fraction, and texture.

Redox Properties Measured in the ETEM. Reduction and oxidation (redox) properties is a key aspect in materials’ science. Particularly in catalysis, knowledge of a materials oxidation state under different conditions can provide key insight into its operation. Environmental transmission electron microscopy (ETEM) provides can provided local information both spatially and spectroscopically into the reduction state of materials. In this exercise, will explore the redox properties of a copper using both high-resolution TEM as well as electron energy-loss spectroscopy.

High pressure TEM and catalytic conversion (~1 bar). High-pressure holders facilitates operating conditions (up to 1 bar) within the TEM. This is essential for measuring dynamics at the atomic level during catalyst synthesis and test under relevant conditions. In this session, you will get hands-on experience with high pressure TEM. We will guide you through; sample prep, holder set-up, mass spectrometer set-up and image acquisition. The focus of the session will be on the challenges in experiment operation and limitations inflicted by sample-beam interaction of high-pressure in-situ and operando experiments.

Clamped liquid cell TEM session. Liquid-phase transmission electron microscopy (LPTEM) has revolutionized the access to the nanoscale, label-free imaging of a wide variety of liquid processes. Typically, the liquid cells used for LPTEM consist of electron-transparent silicon nitride (SiNx) windows suspended on two physically separated Si chips, which enclose a liquid sample layer with a thickness ranging from a few hundred nanometers to a couple of microns. With LPTEM, NP dynamics, such as nucleation and growth, self-assembly, and interactions, electrochemical processes, biomaterials, and polymers etc. have been studied with sub-nanometer spatial resolution and millisecond temporal resolution.

Nanochannel liquid cell hands-on session. In situ liquid-phase transmission electron microscopy (LPTEM) has been successfully employed to study nanomaterial nucleation, growth, diffusion and interaction, electrochemistry including corrosion, battery chemistry and electrocatalysts, fluid physics, radiation chemistry, biomaterials, and polymers in liquids with sub-nanometer-scale spatial resolution and millisecond temporal resolution [1]. Nanochannel liquid cell with known liquid thickness down to tens of nanometer was developed in 2017 by K. Mølhave group,[2] and is well suited for analytical studies. It has been used to quantify the mean inner potential of water [3] and electron inelastic mean free path in water.[4]  With the latest nanochannel design, one could carry out flow, mixing, and other complex fluid dynamics, and investigate chemical reactions with atomic resolution.

[1]          F. M. Ross, Science 350, aaa9886 (2015).

[2]          S. Laganá, E. K. Mikkelsen, R. Marie, O. Hansen, and K. Mølhave, Microelectron. Eng. 176, 71 (2017).

[3]          M. N. Yesibolati, S. Laganà, H. Sun, M. Beleggia, S. M. Kathmann, T. Kasama, and K. Mølhave, Phys. Rev. Lett. 124, 065502 (2020).

[4]          M. N. Yesibolati, S. Laganá, S. Kadkhodazadeh, E. K. Mikkelsen, H. Sun, T. Kasama, O. Hansen, N. J. Zaluzec, and K. Mølhave, Nanoscale  (2020).

Contact

Jakob Birkedal Wagner
Professor
DTU Nanolab
+45 45 25 64 71